In recent years, regardless of business use or consumer use, ink jet printers have been popularized with technical development of multimedia. The ink jet printers have many characteristics such as ease of multi-coloring and increases in size of images, the capability of printing not only on smooth surfaces but also on uneven surfaces, the capability of on-demand printing, and the like.
Ink jet recording materials including paper as a support have the problem of causing a phenomenon called “cockling” in which the support waves or the problem of worsening the appearance due to breakage when coming into contact with water. In order to resolve the problem, it has been proposed to use an ink jet recording medium including a plastic film as a support and an ink-receiving layer provided on the support and print on the recording medium (refer to, for example, Patent Literatures 1 to 4). Such a medium is excellent in water resistance and can be used as outdoor advertising and poster, a label, wallpaper, and the like. However, a surface of the plastic film has low adhesion to ink jet inks and thus requires a step of forming a layer, which is referred to as an anchor layer, a primer layer, an undercoating layer, an adhesive layer, or the like, on the film surface and then providing the ink-receiving layer composed of polyurethane, polyacryl, or the like as a main component on the layer. This surface treatment step results in an increase in cost and an increase in number of steps, and thus much time is required for production. Further, surface treatment performed by applying a coating material containing a solvent requires a step of removing the solvent contained, and when the solvent is an organic solvent, environmental loading is increased. On the other hand, a recording medium for ink jet has been proposed, in which an ink-receiving agent is not applied, instead micropores are provided in a film surface so that an ink is fixed by being absorbed by the micropores (refer to, for example, Patent Literature 5). However, a stretching step is required, and the film becomes white due to irregular reflection of light by the micropores, thereby limiting application to some of the fields in which transparent is required.